LITTLE ROCK, Arkansas (CNN) -- Two black and two white students sit around a table at Central High School and speak in glowing terms about the racial climate and quality of education at their school -- the only working school designated a National Historic Site.

Little Rock's Central High is hallowed ground for America's civil rights activists. It became a flashpoint in 1957 when, three years after the U.S. Supreme Court ruled segregated schools unconstitutional, President Eisenhower dispatched paratroopers and federalized the state's National Guard to protect nine African-Americans selected to attend the high school.

"In my opinion, we all work closely together," says Richard Torrance, an African-American senior. "We communicate outside of school at events, at sports. Here at Central it's so large that you have to interact or you'll be alone."

But while Central High students sound upbeat about harmony in the hallways, legal and social activists warn that a problem from the past may return to the classrooms in Little Rock and the rest of the nation.

The percentage of white children enrolled in America's public schools -- 60 percent in 2001-2002 -- is 7 percentage points less than a decade before, according to the National Center for Education Statistics.

The Little Rock School District is increasingly becoming racially imbalanced as white parents enroll their children in private and suburban public schools in greater numbers each year. Little Rock's population is 55 percent white and 40 percent African-American. Black students, however, make up about 70 percent of the Little Rock School District's public classrooms, according to the 2000 U.S. Census.

The result, social activists say, is that the Little Rock School District is in danger of moving back to a climate of separation.

The Arkansas capital isn't alone.

As the 50th anniversary of the Supreme Court's historic Brown v. Board of Education ruling is marked, the country's public schools are, in effect, resegregating, according to federal Census and Education Department data.

Educators, federal monitors and civil rights activists are warning that an unequal educational system -- one based on wealth and cutting along racial lines -- is returning to classrooms in Little Rock and the rest of the country, creating a skills gap between white and minority students.

Desegregation peaked in the 1980s

Little Rock's experience mirrors a trend across the country. White students are about twice as likely to attend private school as black students, according to the 2000 Census.

Earlier this year Harvard's Civil Rights Project, a nonprofit research organization, published a report examining trends in public schools. The "Brown at 50" report analyzed Census data, as well as national and local education statistics.

Among the report's major findings: Integration in U.S. classrooms peaked in 1988, but began to reverse at the same time that a 1991 Supreme Court ruling allowed the return of neighborhood schools. (More on the report)

'You've got to have a community'

Central High School appears suddenly in the urban center of Little Rock. Set in a working-class neighborhood of aging wood and brick homes, the massive, two-block wide building seems out of place, more a palace than a school. With an enrollment of about 2,100 students, Central is a public school with a student racial makeup more balanced than many other schools in the Little Rock School District.

Little Rock, like many urban centers across the country, experienced "white flight" from its inner-city neighborhoods and schools beginning in the 1970s, as busing programs expanded as a way to balance student racial proportions.

As the white population began to diminish in the Little Rock district, the tax base began to shrink.

Desegregation in housing patterns and community support for a school district are tied to each other, says Ann Marshall, who heads the Office of Desegregation Monitoring in Little Rock, an arm of the federal courts that supervises desegregation programs there and in the rest of Arkansas.

"You've got to have a community in your schools. That's why they're resegregating," Marshall says. "People with the means to opt out, if they think for any reason that the schools are unsavory, they do so. Then you have a decline of resources."

Harvard's Orfield warned in 1980 that unless Little Rock School District was allowed to merge with the other two city districts where students were increasingly being enrolled, resegregation would happen.

'We're not there'

The same Central High School students who spoke positively about racial cooperation also acknowledge that a division exists. At lunchtime, whites and blacks eat separately, they say. That division reflects the change in residential patterns in the city, one explains.

"We're not 'there'," explains Bryan Hall, a white senior. "Outside of school the environment is still separate. Because we still have separate societies, almost. You can't come to school and expect that just to go away all of a sudden."

Many in educational circles are focusing on how to reverse the resegregation trend. Little Rock School District continues desegregation programs such as magnet schools and majority-to-minority transfer programs.

Magnet schools are schools with a strong emphasis in a particular subject area, and students are selected based on an application process, rather than residence. Majority-minority transfer programs allow students to attend schools in which they are the minority ethnic group.

The front of Central High School in Little Rock.

More work can be done, for example, to boost teacher performance, says Katherine Mitchell, a member of the Little Rock School Board.

Additionally, a current lawsuit claims that not enough is being done to evaluate achievement levels of minority students in the Little Rock district. (Background)

"These are good schools, you can get a good education here," says federal monitor Marshall, who sent her kids to Little Rock's public schools.

"The danger is," she adds, "is if you don't go to the polls and vote for a ... bond issue, you're not going to have the money to support strong public schools. And the public school system does educate most of your citizens."